2022-07-22 10:47 PM
hi,
i have purchased the stm32f746 disco board recently
the disco board stlink connection is in fail, after the i have shorted 5V - GND (big big big mistak..)
i found that this led(LD7) control is in charge st-link mcu (stm32f103)
LD7 Red LED is toggled when i powered on this board
##what does mean this?##
i've checked wave form of m7 oscillator and rtc clock and stm32f103 clock (st-link) using scope
also, 5V to 3V3 power logic is ok
##is this mcu (stm32f7) dead?##
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stupid..
now i can use disco board again.. thanks
cable short was not problem
just usb hub was something worng
none of the pars have not been dead
2022-07-22 11:00 PM
shorted 5V - GND cant kill board, you maybe short some other too ...
2022-07-22 11:16 PM
thank you for replying to me
well, after the logic was shorted, i have eliminated cable lines on board
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LD7 Red LED Toggle notify users something is wrong
but, now i can access to mcu using st link
2022-07-24 08:50 PM
If usb power source is a hub or a pc, it has overcurrent protection (imagine the pc breaks when shorting 5v and gnd through external device, would overwhelm support). Usually there are protection to limit returns to manufacturers...
2022-07-28 07:45 PM
thanks 🙂